Banana-Chocolate Bread

INGREDIENTS

• 1/2 cup (1 stick) unsalted butter, room temperature, plus more for pan
• 1 2/3 cups all-purpose flour (spooned and leveled), plus more for pan
• 1 teaspoon baking soda
• 1/2 teaspoon fine salt
• 1 1/4 cups sugar
• 2 large eggs, room temperature
• 1 1/2 cups mashed overripe bananas (3 to 4)
• 2 tablespoons sour cream
• 1 teaspoon pure vanilla extract
• 6 ounces bittersweet chocolate, chopped